Radial rhythmic chair

ABSTRACT

A chair which moves forwardly and rearwardly in a rhythmic manner on a radius whose center of rotation is located on or near the floor upon which the chair is resting. The chair has a restraint means which prevents the chair from moving forwardly and rearwardly beyond preselected points on the arc described by the radius. The restraint means consists of either flexible members or rigid members pivotally connected and one or two springs which bias the members in a manner to prevent them from assuming a position along a straight line.

United States Patent [191 Kallander RADIAL RHYTHMIC CHAIR [76] Inventor: Charles A. Kallander, 7554 Lynch Road, Sebastopol, Calif. 95472 [22] Filed: Aug. 20, 1971 [21] Appl. No.: 173,492

[52] US. Cl. 297/285 [51} Int. Cl A49!) 19/00 [58] Field of Search 297/264, 265, 266,

[56] References Cited UNITED STATES PATENTS 699,428 5/1902 'Truslow 248/385 3,168,310 2/1965 Strausser... 297/267 3,331,632 7/1967 Lerner 297/302 3,096,963 7/1963 Welsh 248/401 [451 July 3,1973

Primary Examiner-Bernard A. Gelalt Assistant Examiner-Garry Moore Attorney-James R. Cypher 5 7] ABSTRACT A chair which moves forwardly and rearwardly in a rhythmic manner on a radius whose center of rotation is located on or near the floor upon which the chair is resting.

The chair has a restraint means which prevents the chair from moving forwardly and rearwardly beyond preselected points on the are described by the radius. The restraint means consists of either flexible members or rigid members pivotally connected and one or two springs which bias the members in a manner to prevent them from assuming a position along a straight line.

9 Claims, 12 Drawing Figures PATENIEU-ml 3 I975 SIEEIlUFQ INVENTORZ ((ifjfiES A. KALLANDER BYI Z HIS ATTORNEY mm a ma INVENTORI CHARLES A. KALLANDER Q (My HIS ATTORNEY.

PAIENYEUJIJL 3 I973 INVENTORZ HIS ATTORNEY RADIAL RI-IYTHMIC CHAIR BACKGROUND OF THE INVENTION This invention relates to movable chairs and in particular to chairs permitting a backward and forward periodic or rhythmic motion along an arc of a radius whose center of rotation is on or near the floor.

In order to understand the unique motion exerienced in the radial chair described below, a brief review of movable chairs is necessary.

The most familiar movable chair is the rocker. The chair portion of a rocker is mounted on a pair of curved members which are transversely spaced. The motion is similar to sitting at about the center of a large truck tire and rolling the tire back and forth. In a rocking chair, the entire chair is thus moving forwardly and rearwardly and the person experiences a forward and backward motion as well as a rotational sensation.

A further development of th old fashioned rocker is the office executive chair. The executive chair has no forward or backward motion, but the seat does tilt about a point located in close proximity to the underside of the seat. Although an executive chair is more comfortable than a straight chair, it does not approach the rocker in comfort and relaxation.

The third type of movable chair is the old fashioned porch swing in which the seat is suspended from a pivot point above the seated person. The porch swing is merely a development of the familiar childs tree hung swing.

The fourth type of movable chair is not really a movable chair at all. I refer to the ordinary four legged straight backed chair. Everyone, from small boys on up, attempts to make the straight chair more comfortable by rocking the chair back on its back legs. The comfort of such a position is well known, the discomfort experienced from rocking too far back and passing the point of no return is equally familiar but sometimes disastrous.

The striaght back chair is mentioned here in background because it is the one chair that is pivoted or rotated about a radius whose center of rotation is on the floor. The present invention has such a radius and floor mounted center of rotation in common as described below, but here the similarity ends.

SUMMARY OF THE INVENTION The present invention is a movable chair which gives a movement unlike the three movable chairs previously described. Unlike the rocker, the present chair does not roll forward and backward. Unlike the executive chair, the seat does not tilt about a pivot point adjacent the seat. The present chair may be compared with a swing in that the rotational center point is located at a substantial distance from the person seated. While a swing has its center of rotation located abve the person, the essence of the present invention is that the center of rotation is below the person. Thus the person is seated at the end of a long radius located below his seat and the movement is at the end of the radius along the circumference on the arc of the radius.

An integral part of the present radial chair is the forward and rearward restraint system. While rockers and swings have built in restraint systems, tilting and radial chairs do not. Tilting chairs may be restrained by torsion bars, but a radial chair is dealing with much greater forces and the problem is compounded by the fact that the forces build up rapidly in the extreme forward and reverse positions as everyone knows who has tilted a straight back chair too far and gone over backwards.

The essence of the present restraint system is the use of a flexible or a jointed rigid member which restrains forward motion beyond a pre-selected point. A second similar member restrains rearward motion beyond a pre-selected rearward point. A small spring is connected to a point on each of the members between their respective ends. The action of the restraint upon the radial chair is similar to the reaction of a long heavy rope being pulled to make a straight horizontal line. The first principle is that such a feat is impossible and secondly, a small force directed transversely to the longitudinal pull exerts an inordinately large force to prevent further pulling of the rope into a straight line. Although several forms of the invention are shown, all follow this principle.

An objective of the present radial chair is to provide a base which remains in solid contact with the floor while permitting movement along an arc described by the end of a long radius.

Another objective is to provide a movable chair which will not upset either forwardly or rearwardly.

A further objective is to provide a chair which will accommodate a wide range of persons having different weights.

A still further objective is to provide a movable chair having secure and comfortably restrained rotation about a radius whose center of rotation is on or near the floor.

Still another object is to provide a fail safe restraint mechanism in which the chair will not overturn in the event of a failure of the springs.

Another objective is to provide a movable chair which does not stop abruptly at the end of the selected arc.

A further objective is to provide a movable chair in which the springs do not directly receive the entire load.

Another objective is to provide a restraint system which is flexible enough to present a number of attachment locations so that a variety of different designs can be utilized, and in particular, if need be, the springs can be hidden from sight.

A still further objective is to provide a restraint system in which the restraining forces build up rapidly at the terminal points of the swing and smoothly decelerate the rotary motion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of the radial chair constructed in accordance with the present invention. The solid lines represent the position of the chair in the extreme forward position, and the dotted lines represent sent the chair and mechanism in the forward position; and the dashed lines represent the rearward position.

FIG. 5 is a cross sectional view of the chair shown in FIG. taken along the line 33 with still another alternate form of the restraint mechanism. The solid lines represent the chair and mechanism in the forward position; and the dashed lines represent the rearward position.

FIG. 6 is a cross sectional view of the chair shown in FIG. 10 with still another alternate design for the restraint mechanism.

FIG. 7 is a detail of FIG. 6 taken on line 7-7.

FIG. 8 is a detail of FIG. 7 taken on line 8-8.

FIG. 9 is a detail of FIG. 7 taken on line 9-9.

FIG. 10 is a front view of the chair design shown in FIGS. 3-6.

FIG. 11 is a side view of a portion of the chair shown in FIG. 10 with an alternate pivot means.

FIG.'l2 is a front view of the portion shown in FIG. 1 1.

The chair designs shown in FIGS. 1 12 are only representative of the many designs which may be used with the radial concept and the restraint mechanisms shown.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention consists briefly of a seat 6 for receiving a person; a base 7 extending beneath the seat adapted for contact with a floor 8; a frame, here consisting of a seat base 9 and a seat back 11 connected to and supporting the seat and being movable between a forward and rearward position and including a leg such as legs 12 and 13, mounted on the base for rotational movement of the frame and seat about a pivot point 14 positioned on or adjacent the floor; and means connected to the base and the frame for restraining forward and rearward motion of the seat and frame beyond preselected points.

Several ways can be used to mount the chair on a pivot point located on or near the floor. One of such ways is illustrated in FIGS. 1 and 2. A cross member 16 joins the two legs and rotates therewith. A pin 17 is located on the center of rotation such as by drilling an opening in base 7. Openings l8 and 19 are formed in the cross member 16 to receive the pin 17.

The chair of the present invention may be constructed with one or two legs depending upon the stability and esthetic design requirements. The frame and base may be made from wood, steel, plastic or other rigid materials.

Referring to FIG. 1, the restraint means consists of a first member 21 attached to the front of the base at point 22 and extending upwardly and rearwardly; a second menber 23 attached to the rear portion of the base at point 24 and tothe other end of the first member at point 26; a third member effectively divided into two parts 27 and 28 and attached to the intersection point of the first and second members and extending upwardly to an attachmentpoint 29 with the frame; and resilient means 30 connected to a point 31 on the third member and the frame at point 32 biasing the third member to prevent it from assuming a straight line when the seat and frame are in the forward positions.

The extreme versatility of the restraint mechanism may be demonstrated by the number of different kinds of elements with which it may be constructed. For example, since members 21 and 23 do not change position, they may be constructed from rope, cable, rigid bars or point 26 may be mounted on a pedestal attached to base 7 with no separate elements 21 and 23 being required. Thus, the restraint system of FIG. 1 could be constructed from a single member 27 and 28, referred to in the second claim as a first member which is connected to the base at an elevated base point 26 above the floor pivot point 14 and connected at its other end to the frame at a point 29 above the elevated base point. Member 27 28 could be a cable or rope or it could be made up of rigid bars if pivoted at points 26, 31 and 29. The resilient means such as a coil spring 30 acts in the same manner as previously describedie. it is connected to member 27 28, referred to as the first member in claim 2 at a point so that when the chair is rotated to a forward position, the sring will increase its biasing force as the first member more clearly approaches a straight line and when the chair is movdd to a rearward-position, the spring will again increase its biasing force as the first member approaches a straight line.

When the chair in FIG. 1 is moved rearwardly so that the back of the chair rotates through an arc of about 19 degrees and the back reaches the line 11', point 29 travels through an arc to point 29, carrying member 27 to location 27'. Spring 30 as shown in solid line is under tension and assists initially in returning the chair to a neutral position. As the chair reaches the neutral position the spring relaxes somewhat, but as the chair continues to rotate rearwardly, the tension comes back on the spring and resists the rearward motion of the chair. As the chair rotates and the member 27 reaches the position 27', maximum spring tension is exerted because the distance 32-32 is greater than the distance 31-31 and the spring is stretched to a maximum. The greater tension on the spring is only one factor, however, that plays an important part in gently but firmly checking the rearward motion. As may be seen in FIG. 1, at the rearward position of the chair, member 27 reaches a location 27 which more nearly assumes a straight line with member 28 which has not moved to location 28. Thus, while the chair is trying to pull members 27 and 28 into a straight line, the spring force on point 31' is resisting the forces trying to form a straight line. As earlier stated, a small force at point 31' can offset a relatively much larger force acting at points 26 and 29' to pull 27 and 28 into a straight line. Note that pivot point 26 remains stationary throughout the movement of the chair. Point 26 should be placed approximately along a line bisecting the arc of motion of point 29, namely arc 29-29'. It should be further noted that an arc pivoted about point 26 will not coincide exactly, but will approximate the are actually taken by point 29 to point 2.

Still referring to FIG. 1, it may be noted that as the chair approaches the maximum rearward position, and the spring is reaching its maximum tension, there is a considerable return force generated in member 28. Concidentally the moment arm of the return force in member 28 reaches a maximum in the rearward position. The moment arm is the distance from point m on a line extended from 28 to point 14 which is the center of rotation of the chair. Should spring 30 fail at the rear position of the chair, member 27-28 would still restrain the motion of the chair. Thus the design is fail safe.

FIG. 1 shows the chair in the maximum forward position. Note that line 27-28 is not permitted to form a straight line and it also forms an angular relationship with line 23 which is concave upwardly. Spring 30 is partially extended and generates a force in member 28 which acts with a maximum moment arm in the opposite direction to provide a forward stop. The distance from point n on an extension of member 28 to the pivot point 14 represents the moment arm. There is no abrupt stop in either the forward or rearward position, since line 27-28 is-never permitted to form a straight line so long as the spring 30 is operating.

The chair shown in FIGS. 3-6 utilizes the identical principles found in the chair described in FIGS. 1 and 2. Although it is operable, it is schematic in nature to teach the fundamentals of the radial chair and the different restraint mechanisms for controlling the limits of forward and rearward movement. Since certain structural portions of the chair are identical throughout FIGS. 3-6, those identical parts will be given identical part numbers and will not hereafter be further described.

The chair in FIGS. 3-6 comprises a seat 36 for receiving a person; a base 37 extending beneath the seat and adapted to contact the floor 8; a frame connected to and supporting the seat is movable betweena forward and rearward position and includes legs 42 and 43 mounted on the base for rotational movement of the frame and seat about a pivot point 44 positioned on or adjacent the floor; and means connected to the base and frame for restraining forward and rearward motion of the seat and frame beyond preselected points. A coss member 46 joins the legs at the top forming the arm. The seat 36 which may be foam rubber or other fabric is joined to a rigid seat portion 47 which is joined to a rigid back 48 supporting a cushion 49. Identical legs and arm sections are transversely spaced and supported by cross supports 51 at the back, 52 and 53 at the seat and 54 at the floor.

The chair in FIGS. 36 provides an alternative framing method in that two identical pins are located at the outer ends of the cross member 54 and jounaled in the leg sections 42 and 43. It may be stated that the chair in FIGS. 3-6 may also use the identical floor pivot system as shown in FIGS. 1 and 2.

Referring to FIG. 3, a further modification of the restraint mechanism is shown. Briefly, the restraining means comprises: a first member having sections 61 and 62 pivotally connected to the forward end of the base at point 63 and pivotally connected to the frame above the base at point 64, and the first member having a pivot point 66 between the pivotal attachment points; a second member having sections 67 and 68 pivotally connected to the rear portion of the base at point 69 and pivotally connected to the frame above the base at point 64, the second member having a pivot point 72 between the pivotal attachment points; a resilient means 73 connected to the intermediate pivotal points on the first and second members biasing the parts of each of the first and second members to an angular relationship; the first member being positioned to prevent rotation of the frame beyond the rearward position; and the second member being positioned to prevent rotation of the frame beyond the forward position.

As in the restraint mechanism described in FIGS. 1 and 2, the restraint members of FIG. 3 may be made from, rope, cable, chain, other flexible material, or of rigid links. Wherever the word pivot was used in the previous paragraph and in claims for the invention, it

The solid lines in FIG. 3 show the chair in the extreme forward position. Spring 73 has reached its maximum extension for the forward position and holds members 67 and 68 in an angular position to prevent further forward motion. As may be seen, if the spring should break, members 67 and 68 are practically at a straight line and the chair would go forwardly only slightly and then be caught by the member 67 and 68 anchored at points 641 and 69.

The dotted lines in FIG. 3 show the chair in the extreme rearward position. Spring 73 is now in the position 73 and holds members 61 and 62 which have moved to positions 61' and 62. Anchor point 64 has moved to point 64' thus placing member 61 and 62 in practically a straight line. Point 66 will have moved to point 66' and the spring 73 is at its maximum extension. If the spring should fail, the chair will not go over backwards since the length of members 61 and 62 and the point of attachment is designed so that rotation will be arrested.

An alternate design for the restraint mdchanism may be practiced which is but a slight variation of the device shown in FIG. 3. No drawing is shown because it would appear redundant. In this form of the invention, instead of the spring being attached from 66 to 72, it is con nected betwddn one of the following three places; namely, the spring can be attached from 66 to point B, from 66 to point .I, or from 66 to point F. Points, B, J and F are not exactly places but only representative of areas of attachment. Attachment of the spring gives different restraint characteristics in terms of the firmness of the deceleration and the are through which the deceleration occurs.

While the previously described restraint system could be used to restrain rearward motion, a separate system would be required in restraining the forward motion. Here a separate spring could be attached from point 72 to point J. v

In FIG. 3, when the chair is in the rearward position, member 67 moves to position 67", member 68 moves to position 68' and point 72 moves to 72'.

Still another form of the restraint mechanism is shown in FIG. 4. Here the forward restraining means comprises: a first member 76 having an end 77 pivotally connected to the forward end of the base and the other end 78 pivotally connected to the frame above the base, the first member having a pivoted point 79; biasing means 81 connected to the pivot point of the first member and to the frame at point 84, the biasing means biasing the first member so that the parts of the first member always form an angular relationship one to the other; a flexible section member 82 connected to the rear portion of the base at point 83 and connected to a portion of the frame at point 84 above the base, and biasing means 86 connected to spaced points 87 and 66 on the second member between the end connections and biasing the ends of the member toward one another.

One of the novel features of the form of the invention shown in FIG. 4 is the attachment of a spring directly to the member 62. The solid lines show the chair in the extreme forward position so that the member 82 is straight.

When the chair moves rearwardly, the spring will contract and bring the points 87 and 88 closer together thus causing a loop to form in the member between the spring attachment points. While permitting the member 82 to straighten could cause some abruptness at the terminal forward position, this can be remedied by providing a strong spring. Further, when the chair is rotated forwardly, the person using the chair generally will slow the forward motion with his feet against the floor which is not possible in the rearward mode.

The dotted lines in FIG. 4 show the chair in the extreme rearward position. Here, member 76 moves to ',osition 76', member 75 moves to position 75'.and point 79 moves to position 79'. Spring attachment point 84 moves to position 84' thereby stretching spring 81 to a maximum along a location shown as line 81'. Again, it may be noted that the spring 81 prevents members 75 and 76 from being moved into a straight line. This form of the invention is fail safe" also since the spring is not interposed between the attachement at the base 77 and the frame 53. If the spring should e weakened or break, the length of lines 75 and 76 is such as to prevent the chair from going over center and falling backward. Dashed line 48' shows the position of the back of the chair when it is in the extreme rearward position. Point 78' shows the location of point 78 when the chair is in the rearward position.

Another form of the restraining mechanism is shown in FIG. 5. Here the restraining means consists briefly of a first member 182 and 183 pivotally connected to the forward end of the base at point 184 and a pivot point 186 between its ends; a second member 187 and 188 pivotally connected to the rear portion of the base and having a pivot point 189 between its ends, a third member 91 pivotally connected to the frame at point 92 above the base and to the free ends at 93 of the first and second members; and biasing means 94 connected to the intermediate pivot points of the first and second members biasing the respective parts of the first and second members into an angular relationship.

The members of FIG. may be constructed of rope, cable, chain or any flexible material which does not substantially elongate. They also may be constructed from rigid rods or links with pivotal connections at points 184, 186, 93, 92, 189 and at the base 96.

The solid lines show the chair in the extreme forward position. The spring 94 is in the fully extended position and the members 187, 188 and 91 approach, but never quite reach a straight line. The spring pulling at point 189 tends to return the chair to a neutral position.

The dashed lines in FIG. 5 show the chair in the fully rearward rotated position. Member 82 moves to position 82, member 183 moves to position 183', member 91 moves to position 91, member 188 moves to position 188' and member 87 moves to position 87. Spring 94 moves to a position on line 94' with pivot point 93 moving to point 93 and point 189 to 189. As may be seen in the drawing, members 182, 183 and 91 have a specified length so that for a given rotation rearward, these members only approach but do not become a straight line when they are in positions 182', 183' and 91'. Again, the spring is not in the direct line of these members so that even though it should break or become weak, the chair will never go over either frontwards or backwards. The chair is braked to a gentle but firm stop in both the forward and rearward positions since the arrangement of the attachment points is such that the return moment builds up through a relatively substantial arc and then builds up very rapidly near the end of the desired rotation.

FIG. 6 is representative of the type of construction that can be used in any of the previously described figures. It also illustrates an alternate form of biasing system. Referring to FIG. 6, the radial chair shown is the same as those in FIGS. 3-5 and the restraining means consists briefly of a first rigid member 101 pivotally connected to the forward portion of the base at point 102; a second rigid member 103 pivotally connected at point 104 to the other end of said first member; a third rigid member 106 pivotally connected to the free end of the second member at point 108; a fourth rigid member 109 pivotally connected to the rear end of the base at point 111 and extending upwardly and forwardly; a fifth rigid member 112 pivotally connected to the upwardly extending end of the fourth member at point 113, and pivotally connected to the upper end of the second member; spring means 114 connected to the pivotal connection of the first and second members biasing the members to an angular relationship; and spring means 116 connected to the pivotal connection of the fourth and fifth members biasing the members to an angular relationship.

The restraint system of FIG. 6 consists of rigid link members which are pivoted at points 102, 104, 108, 107 113 and 111. Instead of using an extension spring as in the previously described chairs to restrain the chair, torsion springs may be used. It is essential that there is a torsion spring at either pivot point 102 and 104. Likewise the torsion spring may be placed at either point 113 or 111. In order to keep the spring size small, torsion springs may be placed at all four points.

An enlarged view of a typical torsion spring installation is shown in FIGS. 7-9. Base 37 is formed with a recess 121 into which link 101 is recessed and rotatably connected to pin 102. One end of the torsion spring 122 is held in place in a recess 123. The other end of the spring 124 is held in recess 126. The spring constantly urges link 101 in the direction of arrow 127. Another spring 114 is rotatably mounted at pivot 104. Spring end 128 is inserted into recess 129 in link 101 and spring end 131 is recessed in opening 132 in link 103. The torsion spring tends to rotate link 103 in the direction of arrow 133. The ends of the link are splined so that as shown in FIG. 8 link 101 is formed with extension 134 which fits between the recesses formed by forked ends 136 and 137 on link 103. In like manner, links 109 and 112 are formed to accommodate spring 116.

Referring to FIG. 6, when the chair is in the extreme forward position, the restraint members are shown in solid lines. Whdn the chair is in the extreme rearward position, the restraint members are shown in clashed lines. Thus member 101 moves to position 101, pivot point 104 moves to position 104, member 103 moves to position 103', point 108 moves to position 108' and member 106 moves to position 106' with point 107 moving to position 107'. As may be seen in FIG. 6, members 101, 103 and 106 have moved to nearly a straight line. If the springs at the pivot points should fail, the chair would not go over backwards but would be restrained by the members. In the backwards position, member 109 moves to position 109, point 113 moves to position 113' and member 112 moves to position 112'. The back of the chair is at position 48'.

In order to accommodate the desires of different people, the restraining characteristics may be changed in several ways. The points of attachment of the members may be changed which will give greater or less restraint in the forward and backward positions. These changes are rather permanent unless releasable couplings are used at the pivot points. Another way in which the characteristics may be changed is to provide a spring in the forms of the invention found in FIGS. 1-5 which is manually adjustable. Thus tightening the spring will shorten the arc through which the chair can rotate and will increase the restraining force in either the front or rear swings or both.

FIGS. 11 and 12 show a modification of the floor pivot points upon which the frame of the chair is supported. The purpose of this type of pivot is to place the pivot point at thefloor level and to provide a chair which has good lateral stability. In this form of the invention, there is a base 7 which runs longitudinally of the chair and a transverse member 226. At the outer ends of the chair there is a half round member or pin 227 with its flat portion flush with the floor and rounded portion 228 faces upwardly to receive a matching concave portion in the ends of the frame legs 42 and 43. Identical half round pins are provided at both sides of the chair. The half round concave por tions in the legs are identified by the number 229. The floor is identified by number 8.

Th chair of the present invention need not be portable but can be built into the floor of a building to serve as theater seats. The floor" pivot point could be actually located below the floor surface to give an unusually comfortable chair movement. In this form of the invention, the base member 7 would not be needed since the pivot 14 would be set into the floor system and the members normally attached to the base would be attached at convenient places in the floor system.

I claim:

1. A radial rhythmic chair comprising:

a. a seat for receiving a person;

' b. a base extending beneath said seat adapted for contact with a floor; c. a frame connected to and supporting said seat and being movable between a forward and rearward position and including a leg mounted on said base for rotational movement of said frame and seat about a pivot point positioned on or in close proximity to the floor; and d. means connected to said base and said frame for restraining forward and rearward motion of said seat and frame beyond preselected points having, l. a first member having two parts movable to an angular relationship connected to said base and connected at its other end to said frame at a point above said base connection,

2. biasing means connected to said first member at a point between its ends and operatively con nected to said chair at a point so that when said chair is rotated the biasing means will increase its biasing force as the first member more nearly approaches a straight line.

2. A radial chair as described in claim 1 wherein said restraining means comprises:

a. a first member attached to the front of said base and extending upwardly and rearwardly;

b.'a second member attached to the rear portion of said base and to the other end of said first member;

c. a third member attached to the intersection point of said first and second members and extending up wardly to an attachment with said frame, and

d. resilient means connected to a point on said third member and said frame biasing said third member to prevent it from assuming a straight line in the forward and rearward positions of said seat and frame.

3. A radial chair as described in claim 2 including:

a. said third member being positioned in relation to said first member so as to always form less than a straight line relationship therewith when said frame and seat are in the extreme rearward position; and

b. said third member being positioned in relation to said second member so as to always form less than a straight line relationship therewith when said frame and seat are in the extreme forward position.

4. A radial chair as described in claim I wherein said restraining means comprises a. a first member pivotally connected to the forward end of said base and pivotally connected to said frame above said base, and said first member having a pivot point between said pivotal attachment points;

b. a second member pivotally connected to the rear portion of said base and pivotally connected to said frame above said base, said second member having a pivot point between said! pivotal attachment points;

c. resilient means connected to the pivotal points on said first and second members biasing the parts of each of said first and second member to an angular relationship;

d. said first member being positioned to prevent rotation of said frame beyond said rearward position; and

e. said second member being positioned to prevent rotation of said frame beyond said forward position.

5. A radial chair as described in claim 1 wherein said restraining means comprises:

a. a first member having an end pivotally connected to the forward end of said base and the other end pivotally connected to said frame above said base, said first member having a pivoted point between its ends;

b. biasing means connected to the pivot point of said first member and to said frame, said biasing means biasing said first member so that the parts of said first member always form an angular relationship one to the other;

e. a flexible second member connected to the rear portion of said base and connected to a portion of said frame above said base, and

d. tensioning means connected to space points on said second member between the end connections drawing the ends of said member toward one another.

6. A radial chair as described in claim 1 wherein said restraining means comprises:

a. a first member pivotally connected to the forward end of said base and a pivot point between its ends;

b. a second member pivotally connected to the rear portion of said base and having a pivot point between its ends;

c. a third member pivotally connected to said frame above said base and to the free ends of said first and second members; and

d. biasing means connected to the pivot points of said first and second members biasing the respective parts of said first and second members into an angular relationship.

7. A radial chair as described in claim 1 wherein said restraining means comprises;

a. a first rigid member pivotally connected to said 1 forward portion of said base;

b. a second rigid member pivotally connected to the other end of said first member and pivotally connected to said frame above said base;

0. a third rigid member pivotally connected to the rear portion of said base;

d. a fourth rigid mdmber pivotally connected to the other end of said third member and pivotally connected to said frame above said base;

e. spring means connected to the pivotal connection of said first and second member biasing said members to an angular relationship; and

f. spring means connected to the pivotal connection of said third member and said fourth member biasing said members to an angular relationship.

8. A radial chair as described in claim 1 wherein said restraint means comprises:

a. a first member having two parts movable to an angular relationship connected to said base and connected at its other end to said frame at a point above said base connection;

b. a spring connection to said first member and operatively connected to said chair biasing said first member to an angular relationship.

9. A radial chair as described in claim 1 wherein said restraining means comprises:

a first rigid member pivotally connected to said for ward portion of said base;

b. a second rigid member pivotally connected to the other end of said first member;

c. a third rigid' member pivotally connected to said frame above said base and pivotally connected to the-free end of said second member;

(1. a fourth rigid member pivotally connected to the rear end of said base and extending upwardly and forwardly;

. a fifth rigid member pivotally connected to the upward extending end of said fourth member, and

pivotally connected to the upper end of said second member; spring means connected to the pivot connection of said first and second members biasing said members to an angular relationship; and

spring means connected to the pivotal connection of said fourth and fifth members biasing said members to an angular relationship.

Patent No, 2 July 3, 1973 Dated Charles A. Kallander Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 8, "exerienced" should read experienced line 19, "th" should read the line 40, "striaght" should read straight line 57, "abve" should read," above Column 2, line 1, "n" should read in line 63, "FIG. 13" should read I- FIG. 10 Column 3, line 54, "menber" should read member line 63, after "forward" insert and rearward Column 4, line 17, "sring" should read spring line 18, "clearly" should read nearly line 19, "movdd" should read moved line 54, "2'." should read 29' Column 5, line 40, "jounaled"should read journaled line 45, "restralning" should read restraining Column 6, line 27 "mdchanism" should read mechanism line 52 "betwddn" should read between line 35, "exactly" should read exact line 59, "section" should read second Column 7, line 15, ";os ition" should read position line 23, "e" should read be line 64, after "in" insert the line 67, "never" should read not Column 8 line 57 "Whdn" should read When Column 10, line 58, "space" should read spaced Column 11, line 17, "mdmber" should read member Column 12, line 3, "connection" should read connected line 23, "pivot" should read pivotal Signed and sealed this, 19th day of March 1974.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents F ORM P0 1050 (10-69) USCOMM-DC 60876-1 69 U.S. GOVERNMENT PRINTING OFFICE: 1989 O-IiSG-SJL 

1. A radial rhythmic chair comprising: a. a seat for receiving a person; b. a base extending beneath said seat adapted for contact with a floor; c. a frame connected to and supporting said seat and being movable between a forward and rearward position and including a leg mounted on said base for rotational movement of said frame and seat about a pivot point positioned on or in close proximity to the floor; and d. means connected to said base and said frame for restraining forward and rearward motion of said seat and frame beyond preselected points having,
 1. a first member having two parts movable to an angular relationship connected to said base and connected at its other end to said frame at a point above said base connection,
 2. biasing means connected to said first member at a point between its ends and operatively connected to said chair at a point so that when said chair is rotated the biasing means will increase its biasing force as the first member more nearly approaches a straight line.
 2. biasing means connected to said first member at a point between its ends and operatively connected to said chair at a point so that when said chair is rotated the biasing means will increase its biasing force as the first member more nearly approaches a straight line.
 2. A radial chair as described in claim 1 wherein said restraining means comprises: a. a first member attached to the front of said base and extending upwardly and rearwardly; b. a second member attached to the rear portion of said base and to the other end of said first member; c. a third member attached to the intersection point of said first and second members and extending upwardly to an attachment with said frame, and d. resilient means connected to a point on said third member and said frame biasing said third member to prevent it from assuming a straight line in the forward and rearward positions of said seat and frame.
 3. A radial chair as described in claim 2 including: a. said third member being positioned in relation to said first member so as to always form less than a straight line relationship therewith when said frame and seat are in the extreme rearward position; and b. said third member being positioned in relation to said second member so as to always form less than a straight line relationship therewith when said frame and seat are in the extreme forward position.
 4. A radial chair as described in claim 1 wherein said restraining means comprises : a. a first member pivotally connected to the forward end of said base and pivotally connected to said frame above said base, and said first member having a pivot point between said pivotal attachment points; b. a second member pivotally connected to the rear portion of said base and pivotally connected to said frame above said base, said second member having a pivot point between said pivotal attachment points; c. resilient means connected to the pivotal points on said first and second members biasing the parts of each of said first and second member to an angular relationship; d. said first member being positioned to prevent rotation of said frame beyond said rearward position; and e. said second member being positioned to prevent rotation of said frame beyond said forward position.
 5. A radial chair as described in claim 1 wherein said restraining means comprises: a. a first member having an end pivotally connected to the forward end of said base and the other end pivotally connected to said frame above said base, said first member having a pivoted point between its ends; b. biasing means connected to the pivot point of said first member and to said frame, said biasing means biasing said first member so that the parts of said first member always form an angular relationship one to the other; c. a flexible second member connected to the rear portion of said base and connected to a portion of said frame above said base, and d. tensioning means connected to space points on said second member between the end connections drawing the ends of said member toward one another.
 6. A radial chair as described in claim 1 wherein said restraining means comprises: a. a first member pivotally connected to the forward end of said base and a pivot point between its ends; b. a second member pivotally connected to the rear portion of said base and having a pivot point between its ends; c. a third member pivotally connected to said frame above said base and to the free ends of said first and second members; and d. biasing means connected to the pivot points of said first and second members biasing the respective parts of said first and second members into an angular relationship.
 7. A radial chair as described in claim 1 wherein said restraining means comprises; a. a first rigid member pivotally connected to said forward portion of said base; b. a second rigid member pivotally connected to the other end of said first member and pivotally connected to said frame above said base; c. a third rigid member pivotally connected to the rear portion of said base; d. a fourth rigid mdmber pivotally connected to the other end of said third member and pivotally connected to said frame above said base; e. spring means connected to the pivotal connection of said first and second member biasing said members to an angular relationship; and f. spring means connected to the pivotal connection of said third member and said fourth member biasing said members to an angular relationship.
 8. A radial chair as described In claim 1 wherein said restraint means comprises: a. a first member having two parts movable to an angular relationship connected to said base and connected at its other end to said frame at a point above said base connection; b. a spring connection to said first member and operatively connected to said chair biasing said first member to an angular relationship.
 9. A radial chair as described in claim 1 wherein said restraining means comprises: a first rigid member pivotally connected to said forward portion of said base; b. a second rigid member pivotally connected to the other end of said first member; c. a third rigid member pivotally connected to said frame above said base and pivotally connected to the free end of said second member; d. a fourth rigid member pivotally connected to the rear end of said base and extending upwardly and forwardly; e. a fifth rigid member pivotally connected to the upward extending end of said fourth member, and pivotally connected to the upper end of said second member; f. spring means connected to the pivot connection of said first and second members biasing said members to an angular relationship; and g. spring means connected to the pivotal connection of said fourth and fifth members biasing said members to an angular relationship. 